devex: Add script to bake in local options for Playwright runs (#6668)

## Summary

Try it out: `pnpm test:browser:local`

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6668-devex-Add-script-to-bake-in-local-options-for-Playwright-runs-2aa6d73d36508130b1d6d0b2e79a4641)
by [Unito](https://www.unito.io)

playwright.config.ts

@@ -1,27 +1,32 @@
 import { defineConfig, devices } from '@playwright/test'
+import type { PlaywrightTestConfig } from '@playwright/test'
+
+const maybeLocalOptions: PlaywrightTestConfig = process.env.PLAYWRIGHT_LOCAL
+  ? {
+      // VERY HELPFUL: Skip screenshot tests locally
+      // grep: process.env.CI ? undefined : /^(?!.*screenshot).*$/,
+      timeout: 30_000, // Longer timeout for breakpoints
+      retries: 0, // No retries while debugging. Increase if writing new tests. that may be flaky.
+      workers: 1, // Single worker for easier debugging. Increase to match CPU cores if you want to run a lot of tests in parallel.
+
+      use: {
+        trace: 'on', // Always capture traces (CI uses 'on-first-retry')
+        video: 'on' // Always record video (CI uses 'retain-on-failure')
+      }
+    }
+  : {
+      retries: process.env.CI ? 3 : 0,
+      use: {
+        trace: 'on-first-retry'
+      }
+    }
 
 export default defineConfig({
   testDir: './browser_tests',
   fullyParallel: true,
   forbidOnly: !!process.env.CI,
   reporter: 'html',
-  // /* // Toggle for [LOCAL] testing.
-  retries: process.env.CI ? 3 : 0,
-  use: {
-    trace: 'on-first-retry'
-  },
-  /*/ // [LOCAL]
-  // VERY HELPFUL: Skip screenshot tests locally
-  // grep: process.env.CI ? undefined : /^(?!.*screenshot).*$/,
-  timeout: 30_000, // Longer timeout for breakpoints
-  retries: 0, // No retries while debugging. Increase if writing new tests. that may be flaky.
-  workers: 4, // Single worker for easier debugging. Increase to match CPU cores if you want to run a lot of tests in parallel.
-
-  use: {
-    trace: 'on', // Always capture traces (CI uses 'on-first-retry')
-    video: 'on' // Always record video (CI uses 'retain-on-failure')
-  },
-  //*/
+  ...maybeLocalOptions,
 
   globalSetup: './browser_tests/globalSetup.ts',
   globalTeardown: './browser_tests/globalTeardown.ts',